"I have long been impressed by the strength of the Phillips 66 business portfolio," he said of the deal in a press release. "The flow improver business is a high-quality business with consistently strong financial performance, and it will fit well within Berkshire Hathaway."

Buffett Cashing in on All Facets of Big Oil

Few understand the increasing importance of freight rail transportation of oil better than Buffett. But he also understands it's not an either-or choice: pipelines also are key for moving oil to targeted markets.

Far from "either-or," for Buffett then, it's a game of investing in "all of the above" of Big Oil's assets.

"Dodged a Bullet"

In the aftermath of the BNSF's massive freight train explosion in Casselton, Mayor Ed McConnelltold the press the city with 2,329 citizens was lucky to have "dodged a bullet," with no fatalities from the disaster.

"There have been numerous derailments in this area," he told The Associated Press. "It's almost gotten to the point that it looks like not if we're going to have an accident, it's when. We dodged a bullet by having it out of town, but this is too close for comfort."

In July 2013, another "bullet" came in the form of a freight train carrying oil obtained via fracking in North Dakota's Bakken Shale. That one exploded in the town of Lac-Mégantic, Quebec, killing 47 people.

With the freight rail industry carrying unprecedented levels of oil to market and rail car explosions happening with greater frequency -- led in the forefront by BNSF -- it's an industry with many serious safety questions to answer as we turn the page to 2014.